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3 years ago

Please help me with this question.

Mathematics

1 answer:

CaHeK987 [17]3 years ago

4 0

Answer:

Step-by-step explanation:

Let's say that R, N, and M are the ages of Ric, Nancy, and Michael in 1980.

We can write three equations:

R = 2N

N = 2M

(R + 12) + (N + 12) + (M + 12) = 78

Simplify the third equation:

R + N + M + 36 = 78

R + N + M = 42

Substitute the first equation:

2N + N + M = 42

3N + M = 42

Substitute the second equation:

3(2M) + M = 42

6M + M = 42

7M = 42

M = 6

Therefore:

N = 12

R = 24

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3 years ago

Hi guys please help meee

Lisa [10]

<h3>Answer: 10</h3>

=======================================================

Explanation:

We'll start off converting each mixed number into an improper fraction.

The formula to use is $A \frac{b}{c} = \frac{A*c+b}{c}$

So,

$A \frac{b}{c} = \frac{A*c+b}{c}\\\\2 \frac{1}{8} = \frac{2*8+1}{8}\\\\2 \frac{1}{8} = \frac{16+1}{8}\\\\2 \frac{1}{8} = \frac{17}{8}\\\\$

And,

$A \frac{b}{c} = \frac{A*c+b}{c}\\\\2 \frac{2}{3} = \frac{2*3+2}{3}\\\\2 \frac{2}{3} = \frac{6+2}{3}\\\\2 \frac{2}{3} = \frac{8}{3}\\\\$

So the task of computing $2 \frac{1}{8} \times 2 \frac{2}{3}$ is exactly the same as computing $\frac{17}{8} \times \frac{8}{3}$

Notice how we have an 8 up top and an 8 down below. Those 8's cancel out and we're left with $\frac{17}{3}$ . That fraction does not reduce any further.

The last step is to convert that improper fraction result to a mixed number.

$\frac{17}{3} = \frac{15+2}{3}\\\\\frac{17}{3} = \frac{15}{3}+\frac{2}{3}\\\\\frac{17}{3} = 5+\frac{2}{3}\\\\\frac{17}{3} = 5 \frac{2}{3}\\\\$

Or you could note that 17/3 leads to 5 remainder 2. The 5 is the whole part and the 2 forms the numerator of the fractional part 2/3.

The value is in $A \frac{b}{c}$ form where

A = 5
b = 2
c = 3

Therefore, A+b+c = 5+2+3 = 10

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